Device and method for packaging flat articles conveyed in a conveying stream

ABSTRACT

The invention is related to a device and to a method for packaging flat articles ( 10 ) conveyed in a conveying stream, in particular printed products, with a packaging material. The device includes a conveying device ( 24 ) for conveying the flat articles in a conveying direction (F), as well as a processing means ( 16 ) for producing an at least partially closed envelope ( 20 ) out of packaging material. Apart from this, an onward conveying device ( 26 ) for conveying onwards articles ( 10 ) enveloped with envelopes ( 20 ) out of packaging material is present. Because as a result of errors in feeding-in, in particular gaps in the incoming conveying stream, it is possible that empty envelopes are produced, in accordance with the invention a transfer device ( 28 ) is arranged downstream of the processing means ( 16 ). This is capable of removing from the conveying stream empty envelopes ( 22 ) produced without the inclusion of an article ( 10 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is related to the field of materials-handling and packaging technology and concerns a device and a method for packaging flat articles conveyed in a conveying stream in accordance with the generic term (preamble) of the claims. The device according to the invention serves for the packaging of flat articles, for example, of individual printed products, of stack-shaped groups of printed products or of stack-shaped groups of printed products and other flat articles, such as, for example, CDs, flat sample articles or flat sample bags.

2. Description of Related Art

From EP-A 0 712 782 or WO 2005/118402, for example, it is known how to pack flat articles of the type mentioned above with the help of a so-to-say endless packaging material web, e.g., a plastic foil or paper web fed-in from a roll. In doing so, at least one packing material web is placed around articles being conveyed in a row one after the other and at a distance from one another, or at least one packaging material web is fed-in on both sides to a row of this kind. Thereupon the packaging material web is closed transverse to the longitudinal direction with transverse seams between two successive articles respectively. Possibly, in a longitudinal direction on the top of the row or at its side, longitudinal seams are also produced. In this manner, the articles are enclosed by a closed—or only open in longitudinal direction envelope of packaging material. The enveloped articles, resp., the envelopes are normally separated immediately after the establishment of the transverse seams or simultaneously with it.

In case of the utilisation of plastic foil as packaging material, the longitudinal, resp., transverse seams are normally produced by welding, wherein it is possible, that the separation of the packaged articles is carried out simultaneously to the establishment of the transverse seams. In case of the utilisation of paper as packaging material, for example, immediately before the feeding-in of the packaging material web to the row of the articles to be packed at the points of the longitudinal—, resp., transverse seams an adhesive activatable by heat is able to be applied to the packaging material, so that the seams then are capable by being established with similar means to the welded seams on plastic material packagings. It is also possible to close the seams by means of embossing or by other methods known and adapted to the packaging material.

For such processing operations like welding, gluing, etc., printed articles are conveyed in conveying streams to a processing station and conveyed onwards from it again. The processing station advantageously is equipped in such a manner, that the conveying of the packaged articles does not have to be interrupted for the processing, but rather is able to be operated continuously.

A problem in case of such devices with articles continuously conveyed in a conveying stream without any intermediate storage are the envelopes of packaging material, which because of a deficient supply remain empty, for example, when in a regular row of continuously supplied products one or several products are missing (gap). In this case, it is possible, that by transverse connections in the material web or in another manner envelopes are produced, which do not contain a product (empty envelope). The empty envelope is capable of disrupting the onward conveyance and the further processing of the enveloped articles, for example, if it because of the size—and weight differences is not gripped by the onward conveyor. This is particularly applicable in case of high processing—and conveying speeds of several thousand copies per hour, such as occur in the processing of printed products. Here there is the increasing tendency to also protect printed products such as newspapers and magazines with a foil envelope.

BRIEF SUMMARY OF THE INVENTION

The invention is based on the objective of making available a device and a method for the packaging of articles with a web of material, wherein empty envelopes are not capable of disrupting the further processing of the articles.

The device includes a conveying installation for conveying the flat articles in a conveying direction, a processing means for producing, at least partially, e.g., in transverse direction, closed envelopes out of a packaging material with the inclusion of a product as well as a conveying onwards device.

In accordance with the invention, downstream of the processing means an outward transfer (removal) device is located. This is capable of removing empty envelopes, not containing a product, from the conveying stream. The empty envelopes are then able to be collected outside the conveying stream and disposed of. While the conveying stream after the removal of the empty envelope has a gap, in contrast to an empty envelope, however, this gap does not represent a danger of disruption of the further processing and conveying. The gap in the conveying stream is able to be closed again by evening out.

Designated as a conveying stream is the totality of all articles, which are transported by the conveying device, resp., the onward conveying device, resp., the spatial zone covered by them during the transportation. It is limited in a downwards direction by the conveying support, e.g., the conveyor belt of the feeding device, resp., the conveying plane defined by it. By deflecting from the conveying stream, it is understood that the empty envelopes are moved in such a manner that their bottom side at least partially is not in the conveying plane anymore. Preferably, but not limited to, the envelopes are pushed upwards.

The conveying device, in preference, also transports a quasi endless packaging material web. In preference it is a belt conveyor. The articles preferably are arranged in the packaging material web or between two packaging material webs in such a manner, that they are covered by packaging material on both sides. The packaging material web, resp., a part of it, for this purpose is lying on the belt of the conveyor belt. On it there are the products, which in turn are covered with the packaging material from above. With a processing means, e.g., a welding element, transverse connections between an upper zone and a lower zone of the packaging material web are established, in order to produce a closed envelope of packaging material at least at a leading edge as well as at a trailing edge and to enclose and protect the product in this manner. The onward conveying device serves to convey onwards articles enclosed by such envelopes of packaging material; it is also possible that it is a component part of the above mentioned conveying device.

The conveying device may also be capable of serving as a counter tool for the processing means, or else it is also possible, that there are counter tools moved synchronously with the processing means. The processing means is moved up and down or also along a bent closed circulating track, for example, by being fixed to a rigid body or moved along rails. For producing transverse connections in a plastic foil, in preference a welding element, such as that described, e.g., in WO 2005/118402 is utilised.

The transfer device may be able to grip and to remove the empty envelopes from the conveying stream, for example, by means of a movable mechanical element, which is controlled in a suitable manner.

In a preferred further development of the invention, the outward transfer device, however, only comprises construction elements arranged in a stationary way and does without movable parts. In preference these construction elements comprise suction and/or blowing devices, which operate continuously and/or in a controlled manner. With this, it is possible to realise shorter reaction times. As a result, a complicated mechanism and the driving of moving parts become unnecessary, which otherwise would be necessary for implementing the required as short as possible reaction time (immersion into the conveying stream, gripping the empty envelope, removal of the envelope from the conveying stream, return to the starting position) of a moving mechanical element.

In preference, the transfer device comprises a suction device, with which the empty envelopes are sucked from the conveying stream, e.g. in the manner of a vacuum cleaner. The suction device preferably is operated continuously, wherein its suction power is such, that only empty envelopes are sucked up and transported away, not, however, those containing an article. The sucked up empty envelopes are in preference collected in a collecting basket in such a manner, that the suction power of the suction device is not impaired. As an alternative, the sucking up may only take place when an empty envelope is present.

As an alternative to, or in addition to the sucking up, empty envelopes in preference are deflected from the conveying stream with compressed air. By using compressed air, individual envelopes are able to be specifically influenced, wherein nonetheless one is able to do without movable mechanical components, which have to be accelerated. The removed envelopes thereupon in preference, but not imperatively, are able to be sucked up by a suction device as already described. In this, by the deflection it is achieved, that the suction device with the same suction power is able to be located at a greater distance from the conveying plane. As a result, the susceptibility for errors and the passage height of the device (distance from conveying plane to suction element) and with this its flexibility for packaging articles of different thickness is increased.

It is possible that the compressed air is continuous and calculated in such a way, that only empty envelopes are removed, but on the basis of their greater weight no enveloped articles are removed. In a preferred variant, the compressed air is supplied under control, when an empty envelope comes into the zone of influence of the outward transfer device, wherein the supply otherwise is interrupted. Herein it is possible that higher pressures, resp., outflow speeds are used and the empty envelope therefore is very easily deflected, resp., even blown away from the conveying stream.

As a variant to the pure compressed air supply, for the ejecting, for example, a pneumatically driven pusher is conceivable, which also makes a short reaction time possible.

For controlling the compressed and/or suction air supply, in preference a control system is present, which acts in conjunction with a detection device, in particular with an optical sensor. The detection device detects the presence of an empty envelope in the conveying stream, e.g., by measuring the optical transparency or by edge detection, and transmits a corresponding signal to the control system.

Overall a system for the outward transfer of empty envelopes is proposed, which is mechanically simple, is capable of operating with little control technology effort and which has a low susceptibility for errors as well as a high flexibility with respect to the articles to be packaged.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the invention are depicted in the drawings and described in the following. These purely schematically illustrate:

FIG. 1 An overall view of a device in accordance with the invention, which comprises a controlled compressed air nozzle as well as a suction device;

FIGS. 2 and 3 a suction device utilisable in the device from FIG. 1 in two different views;

FIG. 4 a detailed view of a catching basket.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically illustrates an overall view of a device in accordance with the invention with a conveying device 24, a processing means 16, an onward conveying device 26 and a transfer/removal device 28.

With the conveying device 24, here a belt conveyor, articles 10 are transported in the conveying direction F lying on a lower material web 12 and covered with an upper material web 14. Upper and lower material webs 12, 14 normally are connected with one another. The articles 10 in the conveying direction F are at a distance from one another, wherein the distance of the leading edges of two successive articles 10 is normally constant. On the basis of errors in the feeding-in, it is, however, also possible, that there are gaps in the conveying stream; the mentioned distance then amounts to, for example, double the normal distance.

The processing means 16 serves to produce transverse connections 18 between the upper and the lower material webs 12, 14 and therefore to split-up the packaging material tube into individual envelopes (packages) 20 transverse to the conveying direction F, which here each respectively contain one article 10. The individual packages 20 are separated by lateral material displacement during or shortly after the production of the transverse connections, e.g., during the welding of a foil seam. In case of a gap in the fed-in conveying stream, an empty envelope 22 of packaging material is produced, because the processing means 16 also processes the material webs 12, 14 at a gap. It is possible that envelopes are produced, the length of which is greater than a typical product length, e.g., when several articles are missing behind one another and the transverse welding is interrupted.

The onward conveying device 26, which in preference conveys at a higher speed than the conveying device 24, serves to convey the enveloped products 10, resp., envelopes 20 in a continuous conveying stream. The filled envelopes 20 (resp., their bottom sides) are moved in a conveying plane E, which here, for example, is defined by the conveying support 26′ (conveyor belt, conveyor strap) of the onward conveying device 26.

The transfer device 28 serves to remove the empty envelopes from the conveying stream. It is arranged downstream of the processing means 16 and here is located in the zone of the onward conveying device 26; it is also possible, however, that it is arranged between the conveying device 24 and the onward conveying device 26 or in the zone of the conveying device 24. The outward transfer device 28 comprises a controlled compressed air supply 30 as well as a suction device 40.

The compressed air supply 30 comprises a compressed air nozzle 31, a compressed air source 32, e.g., a compressor or a compressed air reservoir. The connection between the compressed air nozzle 31 and the compressed air source 32 is capable of being specifically opened, resp., closed by means of a controllable valve 34. The opening 31′ of the compressed air nozzle 31 is arranged in the vicinity of the conveying plane E, so that it is possible to specifically exert an influence on the conveying stream. Here the compressed air nozzle 31 is arranged in the zone between two partial conveyors, out of which the onward conveying device 26 is constructed. The distance between the partial conveyors here is depicted exaggerated. Any element, which limits the air stream laterally, is capable of serving as compressed air nozzle 31, e.g., also a hole in a supporting substrate of the onward conveying device 26. It goes without saying, that instead of air it is also possible to utilise another gas.

For controlling the compressed air supply, resp., the valve 34, there is a control device 36. This receives a signal from a detection device 38, e.g., an optical sensor, which indicates the presence of a gap, resp., of an empty envelope 22 in the conveying stream. This signal makes the control system 38 enable the compressed air supply at the point in time, at which the empty envelope is being conveyed in the zone of the compressed air nozzle 31. Thereupon the empty envelope 22 is deflected from the conveying stream in an upwards direction.

The suction device 40 is located above the compressed air nozzle 31. It operates continuously. Its suction power and its distance from the conveying plane E is selected in such a manner, that empty envelopes 22 deflected from the conveying plane are sucked off and removed, not, however, products in envelopes 20. By the compressed air pulse therefore, with the same suction power the distance of the suction tube opening from the conveying plane E can be greater than without a compressed air pulse. The distance, in preference, is selected to be so great, that a conveying through or away of products with a predefined maximum thickness is possible.

The empty envelopes 22 are transported away through the suction tube 42, collected and disposed of. The uninfluenced products 20 are conveyed on, and if so required, further processed.

The device demonstrated and described above is mechanically and control-wise simple, is flexible with respect to the product thickness and operates reliably.

An example for a suction device 40 is illustrated in FIG. 2 in a longitudinal section (vertical to the conveying plane E) as well as in FIG. 3 in cross section (parallel to the conveying plane E). The suction tube 42 already depicted in FIG. 1 leads into a housing 44, which is capable of being closed air-tight, resp., into a catching basket 46 installed in it. The cross section of the suction tube 42 may be round, rectangular or shaped in any other manner; it is also possible, that its area is smaller than that of typical empty envelopes 22, because these as a rule are capable of being deformed. The housing 44 in its bottom plane has a connection 54 for an under-pressure—/suction air source 48, which in an as such known manner, for example, comprises a blower 50 and an exhaust air outlet 52.

The catching basket 46 is at least partially permeable to air and, for example, as a whole or partially consists of a perforated plate. The catching basket 46 here is dimensionally stable, it is, however, also possible that it is as a whole or partially flexible (net, bag).

Because of the following construction of the catching basket and of the housing 44 explained in more detail with reference to FIG. 2-4 it is assured, that the suction power is maintained even if there are already empty envelopes in the catching basket 46.

The catching basket 46 consists of three sheet metal parts 60, 62, 64 arranged in a U-shape. The sheet metal parts 60, 64 form the side walls of the catching basket 46 and are located at a distance from the corresponding side walls of the housing 44. The floor surface 62 of the catching basket 46 is located at a distance from the floor of the housing 44 and therefore also at a distance from the connection 54 for the suction air source 48. In this manner it is assured, that suction air is able to get to the suction tube 42 through the side walls 60, 64 of the catching basket 46, even when empty envelopes 22 cover the as such permeable to air floor surface 62 and thus make it impermeable to air. The lower zone 46 a of the catching basket 46 is permeable to air (e.g., consists of perforated plate), while the upper zone 46 b, in particular the zone around the mouth 43 of the suction tube 42 into the catching basket 46, is impermeable to air. By this it is prevented, that empty envelopes 22 get deposited in the zone around the mouth 43 and with this block the suction air supply through the suction tube 42.

The, in the view in FIG. 4, rear and upper edges of the sheet metal parts 60, 64 adjoin the housing 44, so that the catching basket 46 does not require a ceiling—and back surface of its own. The front of the catching basket 46 is open and here is located at a distance from the front of the housing 44 (not imperative), so that the empty envelopes 22 are capable of being removed simply by opening the housing door 45. 

1. Device for packaging flat articles conveyed in a conveying stream, in particular printed products, with a packaging material, comprising: a conveying device for conveying the flat articles in a conveying direction; a processing means for producing at least partially closed envelopes out of packaging material; an onward conveying device for conveying onward articles enveloped by envelopes out of packaging material; and further comprising a transfer device located downstream of the processing means, which is capable of removing from the conveying stream empty envelopes produced without the inclusion of an article.
 2. Device in accordance with claim 1, wherein an operating zone of the transfer device, that is capable of exerting an effect on the conveying stream, is arranged in the zone of the onward conveying device or between processing means and the onward conveying device.
 3. Device in accordance with claim 2, wherein the transfer device comprises at least one compressed air supply and one suction device, wherein the compressed air supply is capable of deflecting an empty envelope from the conveying stream by blowing in compressed air in such a manner that the deflected envelope renters an area of influence of the suction device and is sucked-off by the suction device.
 4. Device in accordance with claim 3, further comprising a control device, with which the compressed air supply is capable of being controlled in such a manner, that compressed air is blown into the operating zone of the transfer device, when an empty envelope arrives.
 5. Device in accordance with claim 4, further comprising an optical sensor, which is capable of detecting the presence of an empty envelope or of a gap in the conveying stream and of transmitting a corresponding signal to the control device.
 6. Device in accordance with claim 3, wherein the suction device operates continuously.
 7. Device in accordance with claim 3, wherein the suction device comprises a housing, which is essentially capable of being closed air-tight, an at least partially permeable to air catching basket arranged in the housing, a source of under-pressure connected to the housing or located in the housing and a suction tube leading into the catching basket.
 8. Device in accordance with claim 7, wherein the suction tube, source of under-pressure and the catching basket are arranged in such a manner relative to one another, that sucked-off empty envelopes are conducted into the catching basket.
 9. Device in accordance with claim 7, wherein the catching basket is impermeable to air in a first zone and is permeable to air in a second zone, wherein the suction tube leads in at the first zone and a connection to the housing of the source of under-pressure is located in the vicinity of the second zone.
 10. Device in accordance with claim 7, wherein the catching basket, at least in the zone of the connection of the source of under-pressure, is located at a distance from the housing.
 11. Method for the packaging of flat articles conveyed in a conveying stream, comprising the following steps: Conveying the flat articles in a conveying direction, Arranging the flat articles in a packaging material web in such a manner that they are covered by the packaging material on both sides; Producing at least partially closed envelopes out of packaging material; conveying onward of articles enveloped by envelopes of packaging material; and further comprising removing empty envelopes produced without the inclusion of an article from the conveying stream.
 12. Method in accordance with claim 11, further comprising deflecting the empty envelopes from the conveying stream by means of compressed air and subsequently sucking-off the deflected empty envelopes.
 13. Method in accordance with claim 12, further comprising controllably injecting compressed air, when an empty envelope arrives.
 14. Method in accordance with claim 13, further comprising, by means of a detection device, detecting the presence of an empty envelope or of a gap in the conveying stream, and generating a corresponding signal and transmitting it to a control device for controlling the compressed air supply.
 15. Method in accordance with claim 12, further comprising sucking off the empty envelopes by means of a continuously operating suction device.
 16. Method in accordance with claims 12, further comprising collecting the empty envelopes in a catching basket.
 17. Method in accordance with claim 13, further comprising sucking off the empty envelopes by means of a continuously operating suction device. 